Birth, Survival and Growth of Small and Medium Sized Enterprises in Poland: 1990-1994

This research is based on a unique and extensive database which tracks the employment, payroll and sales of individual Polish firms for the period 1990 to 1995. This allowed the authors to calculate the birth, survival and growth rates for different categories of enterprises (state-owned, cooperative, private, foreign-owned and privatised after 1990) and regions. These data match data collected in the United States, making it possible to compare the Polish situation with that of the state of Michigan. Analysis of the data and lessons from the Poland-Michigan comparisons provide a solid basis for the formulation of new policy recommendations for Poland. Allowing for certain important differences, Poland would still seem to need a higher rate of births of new companies. New small private companies and companies with foreign capital can be seen as the main source of job creation and economic revitalisation. To strengthen positive trends in the economy, Poland should create a model of institutional support for both potential entrepreneurs and foreign investors.

[Medium-term results after m. vastus medialis obliquus-plasty for lateral patellar dislocation]

Progressive retropatellar arthrosis is often seen in dated rigid distal realignment (i.e. osteotomy of tuberositas) at long-term follow-ups. Therefore, operations for lateral dislocation of the patella are still discussed controversially. Dynamic, proximal realignments seem to have lower rates of arthrosis but higher rates of redislocation. Recently, in anatomic and biomechanic studies, the m. vastus medialis obliquus (vmo) was found to be one of the most important proximal restraints to lateral dislocation of the patella.A total of 28 patients (mean age 21.5 years) were treated between 1994 and 2003 with a plasty of the vmo for lateral patellar dislocation. The technique was performed for most etiologies of femoropatellar instability.For this proximal soft tissue technique, the muscle tendon is detached from its patellar insertion. Subsequently, the tendon is reinserted at the patella 10-15 mm more distally and fixed with Mitek anchors. Full weight bearing in extension is possible immediately after surgery. An active vastus medialis training is started after 6 weeks.Of the patients, 27 were evaluated clinically and radiologically in 2004 (a mean of 5 years postoperatively). A total of 83% of the patients estimated the result to be good or excellent, 10% were satisfied and 7% were discontent. The mean Lysholm-Knee-Score was 83.1 points. Two patients suffered a patella redislocation (7%). A statistically significant improvement of the congruence angle was noted in the radiographs, even in medium-term controls. In 89% of the cases no or only little retropatellar arthrosis was observed. These 5 year results are comparable to those of other techniques for distal or proximal realignments. The rate of redislocation was below average. Compared to the rate of retropatellar arthrosis in long-term results of rigid distal realignment, our patients demonstrated a relative low rate after 5 years. We attribute this to the minimal interference in physiological joint mechanics and to the restored anatomy. In terms of future long-term results, our findings are promising. The idea of a proximal dynamic stabilization and the causal operative approach at the origin of pathology using vmo-plasty was confirmed in recent anatomic and biomechanic studies. Over or under correction of soft tissues could be adapted. More rigid techniques of distal realignment do not allow an adaptation to this extent and can lead to prearthrotic hyperpression in the medial femoropatellar and femorotibial joints.

[The study of apoptosis factors released from laser injured cartilage inducing apoptosis of chondrocyte]

OBJECTIVE: To explore the role of pro-apoptotic signals following tissue injury and how these may promote a progression of further cell death. METHODS: Laser treated porcine articular cartilage disks were maintained in culture media. The collected media at various time periods (3, 6, 9, 12, 24 and 48 h), was called treated conditioned media (TCM). Non-laser treated cartilage disks were used to create control conditioned media (CCM). Each disk was subsequently maintained for 28 days and used in confocal microscopic assessment to document the progression of the damaged area. Isolated porcine chondrocytes were cultured in monolayer, and were exposed to TCM, CCM or normal culture medium (NM). As a positive inducer of apoptosis, the monolayer cells were exposed to UV radiation for 10 min and cultured in NM. Following 24 h exposure, the cells were harvested and stained with the appropriate combination of fluorescent dyes and processed via flow cytometry. RESULTS: All cultured cells exposed to TCM displayed a caspase-3 positive subpopulation, a loss of CMXRos, and with a reduced or lost NO signal. CCM exposure signals were comparable to the NM treatments with all having retained CMXRos, NO and without evidence of caspase-3 activity. UV treatment also induced a reduction in NO, but both CMXRos and caspase-3 positive, representing an earlier stage of apoptosis and suggesting that the mode of cell death via UV and TCM exposure are via different processes. The investigation of a dose (100%, 50%, 25% and 12.5%) and time (0.5, 1, 3, 9, 12 h) response to TCM exhibited that all treatments observed an increase in caspase-3 positive cells and a reduction in NO and CMXRos. CONCLUSION: The usefulness of FCM can be used in the study of cell viability and apoptosis. Such a system may be useful in the study of mechanisms of disease such as osteoarthritis, thus may be of practical use for the pharmaceutical industry for screening associated drugs.

Radioprotection of cultured cells by preincubation in medium containing deuterium oxide

Pretreatment with deuterium oxide (D2O) has been shown to protect mice against lethal effects of X-rays. In contrast, X-irradiation of cultured mammalian cells in D2O-containing medium has previously been reported to result in increased cell killing. Therefore, the effects of preincubation in medium containing 20% D2O on radiosensitivity were tested, using cells of a heat-sensitive cell-cycle mutant (21-Tb) of the murine mastocytoma P 815-X2. The mutant cells proliferate at 33 degrees C and are arrested in G1 phase in a state of reversible proliferative quiescence at 39.5 degrees C. Prior to irradiation with single X-ray doses of 0-10 Gy, the cells were cultured in normal or D2O-containing medium, either for 96 h at 33 degrees C ('proliferating cells'), or for 72 h at 33 degrees C followed by 24 h at 39.5 degrees C ('arrested cells'). After X-irradiation the cells were resuspended in normal medium, and cell survival was determined by the capacity of cells to form colonies in fibrin gels. Preincubation in medium containing 20% D2O resulted in a radioprotective effect on both proliferating and arrested cells, particularly at the higher X-ray doses. This radioprotection was manifested as a decreased slope of the semilogarithmic survival curves, whereas pretreatment with D2O had no significant effect on postirradiation repair as judged from Dq values. These results support the interpretation that the increase in postirradiation survival may be attributed to incorporation of deuterium into cellular metabolites during the period of preincubation.

Perioperative fluid management: comparison of high, medium and low fluid volume on tissue oxygen pressure in the small bowel and colon

BACKGROUND AND OBJECTIVE: Insufficient blood flow and oxygenation in the intestinal tract is associated with increased incidence of postoperative complications after bowel surgery. High fluid volume administration may prevent occult regional hypoperfusion and intestinal tissue hypoxia. We tested the hypothesis that high intraoperative fluid volume administration increases intestinal wall tissue oxygen pressure during laparotomy. METHODS: In all, 27 pigs were anaesthetized, ventilated and randomly assigned to one of the three treatment groups (n = 9 in each) receiving low (3 mL kg-1 h-1), medium (7 mL kg-1 h-1) or high (20 mL kg-1 h-1) fluid volume treatment with lactated Ringer's solution. All animals received 30% and 100% inspired oxygen in random order. Cardiac index was measured with thermodilution and tissue oxygen pressure with a micro-oximetry system in the jejunum and colon wall and subcutaneous tissue. RESULTS: Groups receiving low and medium fluid volume treatment had similar systemic haemodynamics. The high fluid volume group had significantly higher mean arterial pressure, cardiac index and subcutaneous tissue oxygenation. Tissue oxygen pressures in the jejunum and colon were comparable in all three groups. CONCLUSIONS: The three different fluid volume regimens tested did not affect tissue oxygen pressure in the jejunum and colon, suggesting efficient autoregulation of intestinal blood flow in healthy subjects undergoing uncomplicated abdominal surgery.

Comparison of neutral oral contrast versus positive oral contrast medium in abdominal multidetector CT

To determine whether neutral contrast agents with water-equivalent intraluminal attenuation can improve delineation of the bowel wall and increase overall image quality for a non-selected patient population, a neutral oral contrast agent (3% mannitol) was administered to 100 patients referred for abdominal multidetector row computed tomography (MDCT). Their results were compared with those of 100 patients given a positive oral contrast agent. Qualitative and quantitative measurements were done on different levels of the gastrointestinal tract by three experienced readers. Patients given the neutral oral contrast agent showed significant better qualitative results for bowel distension (P < 0.001), homogeneity of the luminal content (P < 0.001), delineation of the bowel-wall to the lumen (P < 0.001) and to the mesentery (P < 0.001) and artifacts (P < 0.001), leading to a significant better overall image quality (P < 0.001) than patients receiving positive oral contrast medium. The quantitative measurements revealed significant better distension (P < 0.001) and wall to lumen delineation (P < 0.001) for the patients receiving neutral oral contrast medium. The present results show that the neutral oral contrast agent (mannitol) produced better distension, better homogeneity and better delineation of the bowel wall leading to a higher overall image quality than the positive oral contrast medium in a non-selected patient population.